(CNN)Presumptive Republican nominee Donald Trump faces all the familiar problems that previous GOP standard bearers have confronted over the last six cycles: awful numbers among young voters, women, Latinos and African-Americans.

But Trump, who dominated the GOP primaries by first running up his numbers among blue collar whites and then expanding beyond that economic demographic, has another problem that other GOP nominees didn't have.

Behind that gap is Trump's relative weakness among white voters, a group that any GOP nominee must capture to be competitive in a general election. Trump gets 52% of white voters according to the poll, with Clinton getting 43%.

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Sounds like a rout, right? Wrong.

By contrast, Mitt Romney won 59% of white voters in 2012, beating President Barack Obama solidly among white men and women. (Romney still lost the election by 5 million votes.)

A deeper look at the numbers finds Trump losing white women by 2 points, a group that Romney won by 14 points. Romney won white men by 27 points. Trump is winning them by 18 points.

Clinton's (relative) strength among white voters, echoes Obama's first campaign and Bill Clinton's 1996 re-election bid when they both captured 43% of the white vote and dominated the electoral map.

While it's clear that Trump's comments about Latinos and Muslims have hurt his numbers, depressing his numbers among non-whites, the comments are also causing a drag on his numbers on white voters.

Like previous GOP nominees, Trump struggles with non-white voters, gaining only 14% to Clinton's 81%. But his general election hurdles could extend to white voters as well, a problem masked by his dominance in the GOP electorate.

Even before she got in the race, the early argument around a Clinton candidacy was that she would likely do better than Obama among white voters in a general, perhaps putting states like Kentucky in play. That seems unlikely. But her strength among the Obama coalition, coupled with Trump's (relative) weakness among white voters, could give her an unexpected electoral boost and add to Trump's already long to-do list.